Is it possible to change shortcuts for the add menu?
No, blender GUI  was not designed with that in mind, it's something I've tried to do for a long time.
We can only hope or ask developers to give us facilities to customize menu shortcuts.

Here are some discussions that I started on this topic:


How to customize a Menu
Ayuda con los menus ( Spanish )


Personally I think it is quite necessary because many users require this. I think we should begin to wonder where can we make requests to the developers?